4-Hydroxy-2H-1,2-benzothiazine-3-carbohydrazide 1,1-dioxide-oxalohydrazide (1:1): X-ray structure and DFT calculations

X-ray diffraction analysis benzothiazine oxalohydrazide DFT Mulliken atomic charge molecular electrostatic potential

МАГНЕТИЗМ И БИРАДИКАЛОИДНЫЙ ХАРАКТЕР p-АРОМАТИЧЕСКИХ И АНТИАРОМАТИЧЕСКИХ СИСТЕМ В СИЛЬНОМ МАГНИТНОМ ПОЛЕ, КРИСТАЛЛИЧЕСКАЯ СТРУКТУРА МОНОГИДРАТА ТЕТРАБРОМИДОДИХЛОРИДОСТАННАТА(IV) ЭНРОФЛОКСАЦИНИЯ, ...

The asymmetric unit consists of four independent molecules. <...> The oxalohydrazide molecules have the centre of symmetry at the mid-point of the central C—C bond. <...> An extensive three-dimensional supramolecular network of N—H…N, N—H…O, C—H…O and O—H…O hydrogen bonds is responsible for crystal structure stabilization. <...> As part of a research program regarding the synthesis of new derivatives of benzothiazine 1,1-dioxides [ 9, 10 ], the synthesis and crystal structure of 4-hydroxy-2H-1,2-benzothiazine-3-carbohydrazide 1,1-dioxide-oxalohydrazide (1:1) is reported here. <...> The title compound was synthesized from commercially available saccharin, which was converted to methyl 4-hydroxy-2H-1,2-benzothiazine-3-carboxylate 1,1-dioxide by a reported procedure [ 11 ] and was subsequently subjected to hydrazinolysis in methanol along with equimolar dimethyl oxalate. <...> It was interesting to note that dimethyl oxalate did not react with benzothiazine hydrazide under these reaction conditions, but reacted with hydrazine and co-crystallized with the product oxalohydrazide. <...> All other H atoms bound to N and O atoms were located in difference maps and refined freely. <...> The geometry optimization of the molecule leading to energy minima was achieved using the B3LYP hybrid exchange-correlation functional with the 6-31G(d,p) basis set [ 17, 18 ]. <...> The optimized molecular geometry, total molecular energy and dipole moment calculations were obtained from the computational process. <...> The asymmetric unit of 1 consists of two oxalohydrazide molecules and two C9H9N3O4S molecules. <...> View of the molecule of 1, showing the atom numbering scheme. <...> Within the selected asymmetric unit, intramolecular O—H…O, N—H…N and N—H…O hydrogen bonds produce S(5)S(6) motifs. <...> According to the above comparisons, it can be deduced that, for the title compound, the biggest differences of the bond lengths and bond angles are mainly found in the groups involved in the hydrogen bonds, which can be easily understood taking into account the intermolecular hydrogen bond interactions present in the crystal. <...> According to the calculated results for Mulliken atomic charge analysis, oxygen and nitrogen atoms, as expected, have larger negative charges relative to other atoms (Table 4). <...> Frontier molecular orbitals and the molecular electrostatic potential. <...> Fig. 3 shows the distributions and energy levels of the HOMO-1, HOMO <...>

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